The field of the application is that of dialysis and renal failure therapy, using a renal failure therapy fluid, whether for hemodialysis or peritoneal dialysis. The invention provides an apparatus and a method for increasing the proportion of wastes from the patient before the renal failure therapy fluid is discarded.
A person's kidneys may fail, and the person may then require dialysis. In some situations, a person must be treated at a dialysis center, such as a hospital or a clinic. In other situations, if the person is able or has a caregiver, dialysis at home is a feasible treatment option. Dialysis may begin with peritoneal dialysis, as a first step, with no direct contact required with the person's blood. After a period of time, the person may require a more effective treatment, hemodialysis.
There are several problems and inconveniences associated with home dialysis. One of the problems is that once treatment begins, a person must continue treatment in order to live, and is thus tied to a bulky, heavy peritoneal dialysis machine or a hemodialysis machine. Another problem is that once home treatment begins, a person becomes accustomed to a particular dialysis machine. It is a burden and an inconvenience if the person has to shift from a peritoneal dialysis machine to an unfamiliar, hemodialysis machine as his or her health deteriorates and hemodialysis becomes necessary. Another disadvantage is that the person, or a caregiver, must handle many heavy bags of dialysis fluid on a daily basis.
Dialysis machines are typically not portable, and are designed for use in the home, as opposed to a design for transportability. Consider, for example, the Aksys PHD machine and the NxStage System One® machine. The AKSYS PHD hemodialysis machine, with markedly improved pre-treatment steps and set-up time, is more compatible with a home environment. However, it requires a water pre-treatment system in the home and may be larger and no more mobile than a conventional hemodialysis machine. The NxStage System One® machine is smaller than a conventional dialysis machine (about 70 lbs or 32 kg) and is thus somewhat portable. This machine does not require installation of a water treatment system in the patient's home and may be connected to a separate device that generate dialysis solution from tap water and concentrates. This separate device, the PureFlow SL, utilizes a replaceable cartridge that includes the necessary filters, deionizers, sorbents, and so forth, and requires attention during processing, in addition to servicing at least once per month for at least the sorbents, filters and deionizers. Alternatively, the machine may use pre-sterilized bags of dialysis solution, another disadvantage of home dialysis.
Another disadvantage is the volume of dialysis fluid used in treatment, whether for peritoneal dialysis or hemodialysis. In a typical treatment session for peritoneal dialysis (PD), about 10-15 liters of dialysis fluid are used. In a typical thrice-weekly hemodialysis therapy, more than about 90 liters of dialysis fluid are used per treatment session. In one example, a dialyzer may require a flow rate of about 500 ml/min for a three-to-four hour period, for a total of about 90-120 liters, about 24 to 32 gallons. This is clearly a large amount.
In home treatment, the patient, or a caregiver, must transport the dialysis fluid from a spare bedroom. Basement, garage, or large closet inside the home, and arrange the bags of fluid near the peritoneal dialysis or hemodialysis machine. Dialysis patients are typically older and in relatively poor health. A caregiver, who may be a spouse or relative of the patient, is also frequently elderly. These people may find burdensome the logistics of transporting, moving, and arranging heavy bags of dialysis fluid. If treatment is conducted three-times weekly, the burden is frequent. If treatment occurs daily, the bags of fluid must then be handled on a daily basis and the burden becomes very frequent.
It would be convenient if the patient were not tied to a large, bulky dialysis machine, and could use the same machine for both peritoneal dialysis and for hemodialysis. It would also be desirable to reduce the amount of dialysis fluid required for treatment, whether for peritoneal dialysis or hemodialysis.